HONG KONG (AP) — Hong Kong authorities on Monday arrested eight people in connection with an unauthorized protest at a university campus last month, police and local media said, amid a widening crackdown on dissent in the semi-autonomous Chinese territory.

The arrests were reportedly made in relation to a demonstration at the Chinese University of Hong Kong in which over 100 people protested a decision to hold graduation ceremonies online. Such ceremonies are often used as a way for students to express political views.

Some protesters had called for Hong Kong's independence, and held up signs that read “Liberate Hong Kong, Revolution of our times,” which are considered to have secessionist notions and are outlawed under the city’s national security law.

Police said they arrested eight people for an unauthorized protest and inciting secession, but did not specify who they were or whether the arrests were related to the university protest.

Arthur Yeung, a graduate from the university who also ran in the city’s district council elections last year, is suspected to be among those arrested. A post on Yeung’s Facebook page said he was arrested at his home on Monday morning.

Two district councillors, Isaac Lee and Eason Chan, were also arrested, according to posts on their respective Facebook pages.

The eight arrested are currently being investigated by national security officers, according to local newspaper South China Morning Post, which cited unnamed sources.

The arrests come as Hong Kong and Beijing have increasingly clamped down on dissent in the city, following Beijing’s imposition of a national security law in Hong Kong in June aimed at curbing months of political unrest and anti-government protests last year.

The crackdown has prompted accusations that Beijing is violating the autonomy it promised when the former British colony was returned to China in 1997. It also has triggered warnings that the ruling Communist Party is damaging Hong Kong’s appeal as a global business center and one of Asia’s most dynamic cities.